Process of sterilizing liquids



L. G. ABOGADO.

PROCESS 0F STERILIZING LIQUIDS.

APPLICATION FILED JUNE 4.1919.

Patented June `21, 1921.

2 SHEETS-SHEET l.

g fluor/mnt 3 noauto@ [his 6. yado L. G. ABOGADO.

PROCESS 0F STERILLZING LIQUIDS.

APPLICATION FILED JUNE 4,1919.

Patented June 21, 1921.

2 SHEETSSHEET 2.

q Gitana# UNITED STATES LUIS Gr. ABOGADO, OF MEXICO, MEXICO.

PROCESS OF STERILIZING LIQUIDS.

Application filed June 4, 1919.

zation of liquids, for example drinking water, through the medium of an electric current passed through such liquid. By the particular novel procedure set forth in detail hereinafter, I form the liquid to be sterilized into a thin flowing film through which a current of relatively low voltage and comparatively high amperage is passed in a direction transverse to vthe main direction of the liquid current, the electrodes being of such a nature as to avoid their being affected by the liquid or by electrolytic action. y

The process will be described in detail hereinafter, and defined, as to its novel fea tures, in the appended claims.

rIhe accompanying drawings illustrate, as examples, three forms of apparatus suitable for carrying out my improved sterilizing process. Figures-1 and 2 are vertical sections, on lines 1-1 and 2-2 respectively of Fig. 3, showing one form pf suchapparatus; Figs. 3 and 4 are horizontal sections on lines 3-3 and 4-4 respectively of Figs. l and 2 respectively; Fig. 5 is a top View of the bottom head or plug employed in this form of the apparatus; Fig. 6 is a vertical central section through another form of the apparaw tus, in a plane corresponding to that of Fi 2; Fig. 7 is a cross section on line 7-7 of ig. 6; and Fig. 8 is a similar cross section of a third form of apparatus.

The apparatus shown in Figs. l to 5 inclusive comprises a bottom casing A, say of circular cross section, made with an inlet A which may be screw-threaded as shown for convenient connection with the threaded end of a liquid-supply pipe (not shown), which pipe would be provided with a cock or valve toregulate or shut' 0H the flow of liquid. An upright shell B has its lower edge seated on a circumferential internal shoulder A of the casing A, the inner sur- Specication of Letters Patent.

Patented June 21, 1921.

serial No. 301,773.

face of said shell (if the shell is made of metal) being coated or lined, as at |B', with enamel, porcelain or other material which will protect the shell from oxidation, which might be caused by chemical or electrolytic action 1f the water or other liquid were allowed to come in contact with the metal surface ofthe shell. The lower end of the shell receives a lowerv head or plug C, fprmed with spaced segmental extensions C vlengaging the inner surface of the shell lining B, while the intervening portions of s aid head are out of contact with the shell lining B', so as to leave two segmental passages, see D, D in Figs. 3 and 5, in permanent communication with a chamber A* formed in the casing A below the head or plug C. At the topV the shell B receives an upper head-or plug E, similar to the head C, but having its entire circumference in engagement with the inner surface of the shell lining B. Each of these heads is lmade with a central aperture through which passes a longitudinal rod F threaded at its ends to receive nuts G, G fitted into suitable recesses in the outer faces of said heads', the latter being connected by said rod and nuts. The nuts are preferably made of insulating material, or at least of non-metallic material, and with closed outer ends, to keep the liquid from contact with the metal rod F. The upper end of the shell B is connected with a ring H, secured, as by screws J, to a cap K provided with an outlet K, which may be connected with any suitable means for carrying away the sterilized liquid; in Figs. 1, 2 and 4 this means consists of a glass outlet pipe L fitted into a rubber bushing L inserted` into the outlet K. The ringH and the cap K together form an upper casing corresponding to the lower casing A. The inner or lower surface of the cap K is provided with a lining I of enamel or other suitable material, to keep the water from contact with the cap, in case the latter is made of metal which might be injured by chemical or electrolytic action if allowed to come in contact with the water. The sc-rews J also serve to hold in place, an additional cap or cover M, of insulating Inaterial, forming with the cap K a chamber N.

Between the two heads C, E, which are made of insulating material, are located the two electrodes O, O', which are alike in shape, each of them comprising two cylinder segments of different diameters connected by a bend lying substantially in an axial plane, said segments being co-axial with the shell B. Preferably, each electrode comprises a core 0', made say of acopper plate, and embedded in a body of carbon or like conducting material indifferent to the action of the electric current and of the water or other liquid to be sterilized. This body of pressed carbon or the like lmay be molded on to the copper core and forms a lining on both sides thereof, as well as at the vertical edges, and even the horizontal upper and lower edges of the electrodes may be covered by such lining, as shown. The said upper and lower edges of the electrodes are fitted into corresponding grooves in the opposing surfaces of the heads C, E, and the large-diameter portion of one electrode is placed adjacent to the small-diameter portion of the other electrode, so that these portions will be parallel and very close together. The spacing of the overlapping electrode portions is uniform at all points of the electrodes. At the center of the apparatus is located a cylindrical heat-retaining body P of carbon or other suitable material, held between theheads C, E by the rodF, which passes through a central perforation of said body. The base and the reduced upper end P of the heat-retaining body P fit into suitable central recesses in the opposing faces of the heads C, E. An annular chamber Q is formed around said reduced portion P, and this chamber cornmunicates at every point of its periphery, with the annular chamber R in which the electrodes O, O are located, it being understood that said electrodes are spaced from the body P so as to leave an annular space or passage between said body and the electrodes. Through apertures E in the head E, the chamber Q communicates with an outlet chamber S formed between the head E and the cap K. As stated above, the two cylinder segments of the same electrode are connected by radial bends, and the bends of the two electrodes are substantially in diametrical alinement, see Figs. 3 and 5; at these bends, the upper edges of the electrodes are provided with projections O* passing through the head E and threaded to receive nuts T. These nuts engage washers U, and where these projections O* extend through the cap K (generally made of metal), they are surrounded by insulating sleeves U', which might be made integral with the (insulating) washers U. The wires 'V for supplying the current pass through a suitable aperture in the cap or cover'M, and

their ends are clamped against the nuts T by binding nuts W ofwellknown character. these terminals being contained in the chamber N, and protected by the cap M.

In operation, the electrodes are connected with a source of electricity furnishing a galvanic current, that is to say, a current of rel* atively low voltage and comparatively high amperage, for example, ive volts and 50 amperes. The water or other liquid, having been turned on, passes through the inlet A into the chamber A*, and from there through the segmental passages D, D into the outer portion of the annular chamber R, adjacent to the shell B. The liquid will then flow first in contact with the outer surfaces of the -outer or lar e-diameter electrode segments,

to rea-ch uprlght slots X formed between the vertical edge of the outer segment of one electrode and the bend of the other electrode. The water or other liquid then enters the space between the two, electrodes O, 0', and forms a iilm of uniform thicknessengaged on opposite faces by the electrodes, said film completing the circuit; that is to say, the circuit remains open until the liquid is in contact with both electrodes. The flow ofthe lquidas substantiallyin a spiralor helical path, being partly circumferential as indicated by the arrows, and partly longitudinal (upward, toward the outlet). Then the liquid reaches the free edges of the inner electrode segments, it will pass inwardly through upright slots Y formed between said free edges and the bends of the other electrodes. -The liquid thus reaches the annular space between the inner electrode segments and the heat-retaining body P, and from this portion of the chamber R the liquid enters the chamber Q adjacent to the head E, and from there passes through the apertures E to the chamber S and the outlet pipe L. 'The current passing through the liquid exerts a heating and sterilizing action thereon, and the water or other liquid is also heated by the heat produced in the electrodesby the passage of the current and thentransferred to the liquid; a certain portion of this electrode heat may be transferred to the liquid even before it reaches the iilm space between the electrodes. It will be noted that in the operation described the cool water is in contact with the inner lining B of the shell B, while the warmer water or liquid is nearer the center or axis of the apparatus; I thus practically prevent the loss of heat which might be due to radiation from the shell. Obviously, the temperature to which the liquid is heated, and also the sterilizing effect of the current, will depend on the time such liquid remains in the apparatus, and this is controlled by opening more or less the cock in the liquidsupply pipe leading to the inlet A. As the electrodes are very close to each other, and spaced uniformly, a very even and efficient heating and sterilizing action is obtained, and any whirling of the liquid in the space between the eledtrodes is obViated. The electrodes are of course of different potential at the time the current passes through the liquid between them. By providing the shell B and the cap K with the protective .electrolytic damage.

linings B and K respectively, I prevent the injury which might result to said parts, if made of metal, either by electrolysis or by a chemical action of the liquid. Similarly, as the electrode Vsurfaces in contact with the liquid are indifferent (non-metallic) the electrodes, and especially their cores O, are protected against oxidation and Part of the heat developed in the apparatus will be absorbed by the heat-retaining body P, which thus becomes a heat-reservoir to equalize, or compensate for, any fluctuations in the heating and sterilizing effect which may be due to irregularities in the flow of the liquid or of the current.

If the supply of liquid is stopped, as by closing the cock in the supply-pipe, the effect will be at first a moderate rise of the amperage, due to the fact that the liquid, now become stationary, is heated to a higher temperature, at which its conductivity is greater; this period of increased amperage is however very brief (generally a few seconds), and then follows a period of reduced amperage owing to the fact that the resistance is increasing progressively as the wetted surface area of the electrodes is diminished by the evaporation of the liquid. Viith the increase of resistance, the heating effect will finally become sufficient to cause the liquid to boil or evaporate, and when the entire amount of liquid in'contact with the electrodes has evaporated, there will be no electrical connection between the electrodes, and the circuit will thus be broken automatically. The steam or vapor produced after the supply of liquid has been shut off, will also travel to the outlet in a spiral path. Generally, the heating effect will be so adjusted as to discharge a liquid at the outlet L; in special cases, however, it might be desired to obtain a sterilized vapor or steam, and a proper regulation of the liquid-supply cock will adjust conditions to secure this result, that is to say, if the cock is opened slightly, liquid may be admitted continuously through the inlet A while steam or vapor is discharged continuously at the4 outlet L. The steam or vapor, whether produced during the continuous admission of liquid or after shutting off the supply, will travel in a spiral path, as does the liquid at the time it fiows between the electrodes.

In the construction illustrated by Figs. 6 and 7, which is adapted for operation by a three-phase current, there are three electrodes O2, O3, O4, each of the general steplike arrangement described in connect-ion withl the electrodes O, O, and also made, say of a carbon body pressed on and around a copper core. Each of the electrodes O2, O3, 0, instead of comprising only two segments of different diameters, has three segments of this character, with intervening bends, and placed so as to form three sets of upright slots X, Y, Z, the three slots of the same set being evenly spaced circumferentially (120 apart), and the outer segment of one electrode overlapping the intermediate segment ofthe next electrode, which intermediate segment again overlaps the inner segment of the .third electrode. All these segments are concentric with the axis of the rod F. There are three terminals or binding posts, one for each of the electrodes. In other respects the construction shown in Figs. G and 7, and its operation, are the same as described with reference. to Figs. 1 to 5.

In Fig. 8 the shell B (with its inner lining Bf) is rectangular instead of cylindrical, and the electrodes O5, O6 are given a corresponding shape. They have inert liquid-engaging surfaces, as before (say lcar- 'bon on a copper core), andV consist of portions of a segmental nature arranged to overlap and to form a spiral path for the thin film of liquid traveling between the electrodes, the opposing, film-engaging faces of the electrodes being evenly spaced at all points of the hn, in each form of the apparatus, and the electric current passing through the film transversely, that is to say, across the film. In other respects, the construction shown in Fig. 8 may agree with those first described, and its operation will be substantially the same as in Figs. 1 to 5.

Various modifications may be made without departing from the nature of my invention as set forth in the appended claims.

After the water has been sterilized as described, impurities contained therein may be removed in any suitable manner, say by attaching a filter' to the outlet tube L, and compelling the water to pass through such filter.

I claim as my invention:

1. The process of sterilizing an electrically-conducting liquid, which consists in passing the liquid, in the form of a film of uniform thickness, in a spiral path, between inert electrodes, and causing a galvanic electric currentfof relatively low voltage and comparatively high amperage) to flow across said film between the electrodes engaging the opposite surfaces of the spirally-Inoving film.

2. The process which consists in passing a galvanic current across a thin film of conducting liquid traveling spirally between inert electrodes, the stopping theflow of the liquid and continuing to pass said galvanio current through the liquid While the latter is stationary, to raise the temperature of the liquid, and removing the resulting vapors in a spiral path. i

8. The 'process which consists in passing a galvanic current across a spirally-moving film of a conducting liquid while absorbing part of the generated heat in a heat-retaining body in contact with said liquid, to compensate `for variations in the galvanic current or in the flow of the liquid.

In testimony whereof I aix my signature.

LUIS G. ABOGADO. 

